cgroup: docs: Mention unbounded protection for memory.{low,min}

I got asked why Memory{Low,Min} don't allow "infinity". They do, but the
docs don't say that like they already do for Memory{High,Max}.

diff --git a/man/systemd.resource-control.xml b/man/systemd.resource-control.xml
index 98a0741359ac770a54bf98ccbe794b82aaa460c7..a832587fa818a9537a50c82267a746d45be6da0b 100644 (file)
--- a/man/systemd.resource-control.xml
+++ b/man/systemd.resource-control.xml
@@ -269,7 +269,9 @@
           <para>Takes a memory size in bytes. If the value is suffixed with K, M, G or T, the specified memory size is
           parsed as Kilobytes, Megabytes, Gigabytes, or Terabytes (with the base 1024), respectively. Alternatively, a
           percentage value may be specified, which is taken relative to the installed physical memory on the
-          system. This controls the <literal>memory.min</literal> control group attribute. For details about this
+          system. If assigned the special value <literal>infinity</literal>, all available memory is protected, which may be
+          useful in order to always inherit all of the protection afforded by ancestors.
+          This controls the <literal>memory.min</literal> control group attribute. For details about this
           control group attribute, see <ulink
           url="https://www.kernel.org/doc/Documentation/cgroup-v2.txt">cgroup-v2.txt</ulink>.</para>
 
@@ -293,7 +295,9 @@
           <para>Takes a memory size in bytes. If the value is suffixed with K, M, G or T, the specified memory size is
           parsed as Kilobytes, Megabytes, Gigabytes, or Terabytes (with the base 1024), respectively. Alternatively, a
           percentage value may be specified, which is taken relative to the installed physical memory on the
-          system. This controls the <literal>memory.low</literal> control group attribute. For details about this
+          system. If assigned the special value <literal>infinity</literal>, all available memory is protected, which may be
+          useful in order to always inherit all of the protection afforded by ancestors.
+          This controls the <literal>memory.low</literal> control group attribute. For details about this
           control group attribute, see <ulink
           url="https://www.kernel.org/doc/Documentation/cgroup-v2.txt">cgroup-v2.txt</ulink>.</para>